21382-82-1Relevant articles and documents
Close the ring to break the cycle: Tandem quinolone-alkyne-cyclisation gives access to tricyclic pyrrolo[1,2-: A] quinolin-5-ones with potent anti-protozoal activity
Szamosvári, Dávid,Sylvester, Kayla,Schmid, Philipp,Lu, Kuan-Yi,Derbyshire, Emily R.,B?ttcher, Thomas
, p. 7009 - 7012 (2019)
Expanding the chemical space of quinolones led to a tandem quinolone-alkyne-cyclisation reaction allowing chemoselective control of the synthesis of tricyclic pyrrolo[1,2-a]quinolin-5-ones. Importantly, we discovered anti-protozoal activity against Plasmodium and Toxoplasma with specific potency of one of the compounds against the liver stage of the malaria parasite in the nanomolar range.
Enantioselective allylation of (2E,4E)-2,4-dimethylhexadienal: Synthesis of (5R,6S)-(+)-Pteroenone
Koukal, Petr,Kotora, Martin
, p. 7408 - 7412 (2015)
Abstract Allylation, trans- and cis-crotylation of (2E,4E)-2,4-dimethylhexadienal, a representative α,β,γ,δ-unsaturated aldehyde, was carried out under different catalytic and stoichiometric conditions. The reactions catalyzed by organocatalysts TRIP-PA and N,N′-dioxides gave the best results with respect to yields, asymmetric induction, and catalyst load in comparison to other procedures. The developed methodology was applied in the enantioselective synthesis of (5R,6S)-(+)-pteroenone, a defensive metabolite (ichthyodeterrent) of the Antarctic pteropod Clione antarctica. Allylation and crotylation of an α,β,γ,δ-unsaturated aldehyde was studied under various conditions. The asymmetric induction was as high as 96 % ee. The anti-crotylation product was used as the crucial intermediate for the enantioselective synthesis of (5R,6S)-(+)-pteroenone, a defensive metabolite of Clione Antarctica.
Total Synthesis of (-)-Hymenosetin
Kauhl, Ulrich,Andernach, Lars,Weck, Stefan,Sandjo, Louis P.,Jacob, Stefan,Thines, Eckhard,Opatz, Till
, p. 215 - 228 (2016)
The 3-decalinoyltetramic acid (-)-hymenosetin and its N-methyl analogue were prepared in 11 and 8 steps, respectively, from (+)-citronellal using an intramolecular Diels-Alder reaction as the key step. This method represents the first example for the synthesis of a 3-decalinoyltetramic acid with a free NH moiety. The stereochemistry of the title compound, an unnatural diastereomer, and of a decalin building block was studied in detail using circular dichroism spectroscopy in the IR and UV/VIS freqeuncy range. This allowed to determine the absolute configuration of the natural product and to plan the synthetic route.
A CONJUGATE OF A TUBULYSIN ANALOG WITH BRANCHED LINKERS
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Paragraph 000277; 000278, (2021/03/02)
The present invention relates to the conjugation of a tubulysin analog compound to a cell-binding molecule with branched/side-chain linkers for having better delivery of the conjugate compound and targeted treatment of abnormal cells. It also relates to a branched-linkage method of conjugation of a tubulysin analog molecule to a cell-binding ligand, as well as methods of using the conjugate in targeted treatment of cancer, infection and autoimmune disease.
Photoenzymatic Generation of Unstabilized Alkyl Radicals: An Asymmetric Reductive Cyclization
Clayman, Phillip D.,Hyster, Todd K.
supporting information, p. 15673 - 15677 (2020/10/18)
Flavin-dependent "ene"-reductases can generate stabilized alkyl radicals when irradiated with visible light; however, they are not known to form unstabilized radicals. Here, we report an enantioselective radical cyclization using alkyl iodides as precursors to unstabilized nucleophilic radicals. Evidence suggests this species is accessed by photoexcitation of a charge-transfer complex that forms between flavin and substrate within the protein active site. Stereoselective delivery of a hydrogen atom from the flavin semiquinone to the prochiral radical formed after cyclization provides high levels of enantioselectivity across a variety of substrates. Overall, this transformation demonstrates that photoenzymatic catalysis can address long-standing selectivity challenges in the radical literature.
Preparation method of zeatin
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Paragraph 0059-0061, (2020/09/23)
The invention provides a preparation method of zeatin, which relates to the technical field of organic synthesis, the preparation method comprises the following steps: reducing 6-trans-(3-methyl-2-alkene-4-butyrate)group-aminopurine to prepare zeatin; according to the brand-new zeatin synthesis route provided by the invention, 6-trans-(3-methyl-2-alkene-4-butyrate)-aminopurine is used as a raw material, is a relatively good solid, is easy to treat, relatively few in synthesis route steps, relatively high in yield and easy to produce and amplify, and further can realize industrial production.
Metal-Free Transfer Hydroiodination of C-C Multiple Bonds
Chen, Weiqiang,Walker, Johannes C. L.,Oestreich, Martin
supporting information, p. 1135 - 1140 (2019/01/11)
The design and a gram-scale synthesis of a bench-stable cyclohexa-1,4-diene-based surrogate of gaseous hydrogen iodide are described. By initiation with a moderately strong Br?nsted acid, hydrogen iodide is transferred from the surrogate onto C-C multiple bonds such as alkynes and allenes without the involvement of free hydrogen iodide. The surrogate fragments into toluene and ethylene, easy-to-remove volatile waste. This hydroiodination reaction avoids precarious handling of hydrogen iodide or hydroiodic acid. By this, a broad range of previously unknown or difficult-to-prepare vinyl iodides can be accessed in stereocontrolled fashion.
A CONJUGATE OF A TUBULYSIN ANALOG WITH BRANCHED LINKERS
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Page/Page column 10; 164-165, (2019/07/17)
The present invention relates to the conjugation of a tubulysin analog compound to a cell-binding molecule with branched/side-chain linkers for having better delivery of the conjugate compound and targeted treatment of abnormal cells. It also relates to a branched-linkage method of conjugation of a tubulysin analog molecule to a cell-binding ligand, as well as methods of using the conjugate in targeted treatment of cancer, infection and autoimmune disease.
REGULATING PLANT GROWTH USING A DIAPOCAROTENOID
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Paragraph 00117, (2019/10/15)
Embodiments of the present disclosure describe diapocarotenoid plant growth regulators represented by formula (I): R-A-R (I) or a precursor, salt, solvate, stereoisomer or polymorph thereof; wherein R is a monovalent carbonyl moiety selected from the group consisting of aldehydes, ethers, diethers, carboxylic acids, alcohols, and ester carboxylates and A is a bivalent polyene represented by the bivalent moiety -(CRa=CRb)x- wherein x is the number of double bonds in polyene moiety A, and Ra and Rb are, independently, hydrogen, a hydrocarbon, or an alkoxy group, and composition of the diapocarotenoid plant growth regulators in an agronomically acceptable carrier. Methods of regulating plant growth including promoting root development, increasing nutrient uptake, enhancing resistance to abiotic stress factors, invigorating plant growth, increasing plant yield, and increasing plant biomass by applying at least one diapocarotenoid plant growth regulator to a seed, plant propagation material, plant or plant growth medium are also described.
Asymmetric Reductive Carbocyclization Using Engineered Ene Reductases
Heckenbichler, Kathrin,Schweiger, Anna,Brandner, Lea Alexandra,Binter, Alexandra,Toplak, Marina,Macheroux, Peter,Gruber, Karl,Breinbauer, Rolf
supporting information, p. 7240 - 7244 (2018/06/15)
Ene reductases from the Old Yellow Enzyme (OYE) family reduce the C=C double bond in α,β-unsaturated compounds bearing an electron-withdrawing group, for example, a carbonyl group. This asymmetric reduction has been exploited for biocatalysis. Going beyond its canonical function, we show that members of this enzyme family can also catalyze the formation of C?C bonds. α,β-Unsaturated aldehydes and ketones containing an additional electrophilic group undergo reductive cyclization. Mechanistically, the two-electron-reduced enzyme cofactor FMN delivers a hydride to generate an enolate intermediate, which reacts with the internal electrophile. Single-site replacement of a crucial Tyr residue with a non-protic Phe or Trp favored the cyclization over the natural reduction reaction. The new transformation enabled the enantioselective synthesis of chiral cyclopropanes in up to >99 % ee.
